Endoceliac physical quantity measuring apparatus having excellent measuring resolution

Abstract

An endoceliac physical quantity measuring apparatus comprises a contact adapted to touch an organic tissue, a vibrator connected mechanically to the contact, a frequency characteristic detecting circuit for detecting parameters associated with the frequency characteristics of the vibrator, load detecting means for detecting a load acting between the organic tissue and the contact, arithmetic means for computing physical quantities of the organic tissue on the basis of the parameters associated with the frequency characteristics detected by the frequency characteristic detecting circuit and the load detected by the load detecting means, and presentation means for presenting the physical quantities computed by the arithmetic means.

We claim: 
     
       1. An endoceliac physical quantity measuring apparatus comprising: a contact adapted to touch an organic tissue;   a vibrator connected mechanically to the contact;   a frequency characteristic detecting circuit for detecting parameters associated with frequency characteristics of the vibrator;   a self-oscillating circuit for subjecting the vibrator to resonance vibration based on a detected vibration state of the vibrator;   load detecting means for detecting a load acting between the organic tissue and the contact;   arithmetic means for, when the load detected by the load detecting means reaches a predetermined threshold value, computing physical quantities of the organic tissue based on the parameters associated with the frequency characteristics detected by the frequency characteristic detecting circuit and the load detected by the load detecting means; and   presentation means for presenting the physical quantities computed by the arithmetic means.   
     
     
       2. An endoceliac physical quantity measuring apparatus according to claim 1, wherein said physical quantities include parameters related to elasticity and density. 
     
     
       3. An endoceliac physical quantity measuring apparatus according to claim 1, wherein said physical quantities include a parameter related to viscosity. 
     
     
       4. An endoceliac physical quantity measuring apparatus according to claim 1, wherein said vibrator includes first and second electrodes, and said oscillating means includes amplifying means for amplifying an output of the first electrode and means for feeding back an output of the amplifying means to the second electrode. 
     
     
       5. An endoceliac physical quantity measuring apparatus according to claim 1, wherein said frequency characteristic detecting circuit includes frequency measuring means for measuring a frequency. 
     
     
       6. An endoceliac physical quantity measuring apparatus according to claim 1, wherein said frequency characteristic detecting circuit includes resonance amplitude measuring means for measuring a resonance amplitude. 
     
     
       7. An endoceliac physical quantity measuring apparatus according to claim 1, wherein said frequency characteristic detecting circuit includes current detecting means for measuring a current flowing through the vibrator. 
     
     
       8. An endoceliac physical quantity measuring apparatus according to claim 1, wherein said self-oscillating circuit includes a band-pass filter in a feedback loop of said oscillating means. 
     
     
       9. An endoceliac physical quantity measuring apparatus according to claim 8, wherein a band-pass frequency of said band-pass filter is different from a resonant frequency of the vibrator in an unloaded state. 
     
     
       10. An endoceliac physical quantity measuring apparatus according to claim 8, wherein a band-pass frequency of said band-pass filter is lower than a resonant frequency of the vibrator in an unloaded state. 
     
     
       11. An endoceliac physical quantity measuring apparatus according to claim 1, wherein said self-oscillating circuit causes the vibrator to vibrate at a fundamental resonant frequency. 
     
     
       12. An endoceliac physical quantity measuring apparatus according to claim 1, wherein said contact, said vibrator, and said load detecting means are connected in succession. 
     
     
       13. An endoceliac physical quantity measuring apparatus according to claim 1, wherein said load detecting means is provided on a fixing member for fixing the vibrator. 
     
     
       14. An endoceliac physical quantity measuring apparatus according to claim 1, wherein said load detecting means is provided integrally with the vibrator. 
     
     
       15. An endoceliac physical quantity measuring apparatus according to claim 1, wherein said load detecting means includes DC voltage detecting means for detecting a DC voltage component generated in the vibrator. 
     
     
       16. An endoceliac physical quantity measuring apparatus according to claim 15, further comprising a third, grounding electrode which is used in common with at least one of the first and second electrodes. 
     
     
       17. An endoceliac physical quantity measuring apparatus according to claim 15, wherein said DC voltage detecting means includes differential voltage detecting means for detecting a difference between an output of the vibrator and an output obtained by passing the vibrator output through a high-pass filter. 
     
     
       18. An endoceliac physical quantity measuring apparatus according to claim 1, wherein said frequency characteristic detecting circuit includes resonance state detecting means for detecting a resonance state, and said arithmetic means computes a physical quantity of the organic tissue based on a feature quantity which is an extreme value of an output of the resonance state detecting means compared with an output of the load detecting means. 
     
     
       19. An endoceliac physical quantity measuring apparatus according to claim 1, wherein said frequency characteristic detecting circuit includes resonance state detecting means for detecting a resonance state, and said arithmetic means computes a physical quantity of the organic tissue based on a feature quantity which is a value of an output of the load detecting means obtained when an output of the resonance state detecting means reaches an extreme value. 
     
     
       20. An endoceliac physical quantity measuring apparatus according to claim 1, wherein said frequency characteristic detecting circuit includes resonance state detecting means for detecting a resonance state, and said arithmetic means computes a physical quantity of the organic tissue based on a feature quantity which is a value of an output of the resonance state detecting means obtained when a value of an output of the load detecting means is constant. 
     
     
       21. An endoceliac physical quantity measuring apparatus according to claim 1, wherein said frequency characteristic detecting circuit includes resonance state detecting means for detecting a resonance state, and said arithmetic means computes a physical quantity of the organic tissue based on a feature quantity which is a value of an output of the load detecting means obtained when a value of an output of the resonance state detecting means is constant. 
     
     
       22. An endoceliac physical quantity measuring apparatus according to claim 1, wherein said frequency characteristic detecting circuit includes resonance state detecting means for detecting a resonance state, and said arithmetic means computes a physical quantity of the organic tissue based on a feature quantity which is a change of an output of the resonance state detecting means compared with a change of an output of the load detecting means. 
     
     
       23. An endoceliac physical quantity measuring apparatus according to claim 1, wherein said frequency characteristic detecting circuit includes resonance state detecting means for detecting a resonance state, and said arithmetic means computes a physical quantity of the organic tissue based on a feature quantity which is a ratio of a change of an output of the resonance state detecting means to a change in an output of the load detecting means immediately after the organic tissue is touched by the contact. 
     
     
       24. An endoceliac physical quantity measuring apparatus according to claim 1, wherein said arithmetic means computes a feature quantity based on a plurality of measuring points on a curve of said load versus said frequency characteristics. 
     
     
       25. An endoceliac physical quantity measuring apparatus according to claim 1, wherein said frequency characteristic detecting circuit includes resonance state detecting means for detecting a resonance state, and said arithmetic means computes a physical quantity of the organic tissue based on a feature quantity which is an extreme value of an output of the resonance state detecting means. 
     
     
       26. An endoceliac physical quantity measuring apparatus according to claim 1, further comprising means for converting a feedback signal from the vibrator into a square form, and for feeding back the converted signal to the vibrator via a band pass filter. 
     
     
       27. An endoceliac physical quantity measuring apparatus according to claim 1, wherein at least a part of said contact is formed of a resin material.